This invention relates generally to radio frequency identification (RFID) systems and methods, and more particularly to a distributed tag reader system and method.
The management and tracking of personnel, assets, and other objects is required in a wide variety of environments, and is often cumbersome, labor intensive, and expensive. Radio receivers and transmitters have been used for many years to identify personnel and objects in such environments. For example, many systems are known for attaching radio tags to items, such as automobiles, so that when automobiles equipped with radio tags enter a certain area, such as a toll booth area, the automobiles are automatically identified and the appropriate tolls are deducted from corresponding accounts, thereby obviating the need for drivers to stop and make payment at toll booths. Innumerable other applications for such radio tag systems have been identified, in areas ranging from inventory control to facility security to sporting event timing.
For security and other access control systems, each access door is typically controlled by a reader system. The reader system typically includes at each door a local transmitter to activate a tag, a receiver to receive and process a response from the tag, and an actuator to control the access door. The reader system is connected to a central controller that determines whether requested access is permitted. Such access control and security systems are expensive to implement due to the equipment needed at each access door. In addition, securing an additional door requires full implementation of a reader system at the access door.
The present invention provides a distributed tag reader system and method that substantially reduce or eliminate disadvantages and problems associated with previously developed systems and methods. In particular, reader functionality is distributed and shared at the receiver and access control levels to improve efficiency and system robustness.
In accordance with one embodiment of the present invention, an access control system includes a plurality of door control systems each associated with an access door and including a relay control for operating the access door and a transmitter for eliciting a radio response from a tag at the access door. The response includes a tag ID and an access door ID. A receiver is operable to receive radio responses from tags at a plurality of access doors. An access door controller is coupled to the receiver and operable to receive the tag ID and the access door ID included in each radio response received by the receiver. The access controller determines whether access by the tag at the access door is authorized and controls the relay door to permit authorized access.
More specifically, in accordance with a particular embodiment of the present invention, the access control system includes a plurality of access controllers, each remote from each other. The access controllers are each coupled to at least one receiver and operable to receive the tag ID and the access door ID included in each radio response received by the receiver, determine whether access by the tag at the access door is authorized, and control the relay control to permit authorized access. An application program interface is coupled to the access controllers and operable to log actions taken by the access controllers.
Technical advantages of the present invention include providing a improved tag reader system and method. In particular, reader functionality is distributed between door control systems, receivers, and access controllers. Receivers are shared by a plurality of access doors to reduce system cost. Access controllers are shared by receivers to further reduce system cost. Receiver ranges may overlap to provide backup processing, thus eliminating the need for duplicate systems at each access door.
Another technical advantage of the present invention includes providing modular components that may be inserted and used at any level in the distributed system and shared between remote units. In particular, memory, processor, communication and other suitable modules are each configured to operate independently of the other. As a result, each component or module may be subtracted or added at any level of system operation.
Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, description, and claims.